twice a day timer

Discussion in 'The Projects Forum' started by jeffledlow, Nov 15, 2012.

  1. jeffledlow

    Thread Starter New Member

    Oct 22, 2012
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    I am trying to build an automatic door for a chicken coop using a power window motor. I already have the up and down circuits wired through relays and limit switches. My problem is I cant seem too find a reliable timer that I can set for up in the morning-time off 12-14 hours, down at night-10-12 hours. I ordered one of the 7 day 14 event timers on E-bay and after waiting 3 weeks it came in from China and doesn't work and even if it did it still wouldn't have the 2 event short term cycle that I need. Ihave looked at the box stores and all they have are 120 volt timers and photocells. I am very limited in knowlege when it comes to building circuits but I can hook them to power supplys with + and - labels
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,085
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    And these won't work for you because you're using a battery? We need to understand your requirements.

    Also, please explain why need a "short term cycle". My timers are in increments of 15 or 30 minutes, so I can turn a light on or off for that 30 minute interval throughout the day. In your system, would it work to turn it on for a half hour at dusk and dawn, then off during the day and night, then back on for another half hour? Your system would need to toggle, so that it reverses direction at each power-on.
     
  3. tshuck

    Well-Known Member

    Oct 18, 2012
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    A microcontroller hooked up to a real-time clock will get the job done... Just a matter of how much electronics knowledge you have...
     
  4. Doktor Jones

    Active Member

    Oct 5, 2011
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    What about using a small uC and just tying a photocell into it so it opens at dawn/closes at dusk? Chickens tend to wake/sleep more by day/night cycle than by any clock, so why bother getting a clock involved in the process in the first place? With a microcontroller you could also tweak it so the door doesn't close until some delay has passed after sunset, to give the late birds time to get back in :)
     
  5. tshuck

    Well-Known Member

    Oct 18, 2012
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    This would be very sketchy... What happens during a lightning storm? Or if someone shines a flashlight on the coop....

    You could counter this by combining the LDR with a RTC so that if, say, the light goes above a certain threshold within 1 hour of sunrise, open the door, and vice versa...
     
  6. Doktor Jones

    Active Member

    Oct 5, 2011
    57
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    Well put the sensor on the roof of the coop (better for catching sunlight anyways) and that will keep it out of sight of most flashlights... and program the microcontroller so that the light-sensing circuit has to stay "on" for 30 seconds continuous before it triggers and opens the door. Don't think I've ever seen a single 30-second lightning flash ;)
     
  7. tshuck

    Well-Known Member

    Oct 18, 2012
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    Not a single bolt, no, but ever seen a lightning storm? Also, what happens on a particularly cloudy day?
     
  8. Don Henry

    New Member

    Nov 26, 2012
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    What about a deer feeder timer? Most can be set from 1 second to 25 or more with 6 feeding a day. Approx cost $25 on the low end. Most are used in conjunction with a solar panel, 12 volt battery and can run for years unattended. One I saw for fish feeding controlled 2 DC motors $90. I have a timer and set it for 3 seconds which is the run time for the window regulator opening or closing. I made a test run without reversing the wires and blew the internal 10amp fuse. I replaced it with a 7.5 and it works fine. I have the problem of making up and down circuits wired with relays and limit switches. I'm a novice with a learning curve. I'm don't think I'll use the limit switches sense the 3 second timer seems to accomplish stopping the motor. Although I don't know if I'll need them for the circuit you used. One posing mentioned Adruino micrcontoller. I'm looking into this.
     
    Last edited: Nov 27, 2012
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